Re: HPET : timer routing setup with Legacy Routing Replacement bit set

From: Andi Kleen
Date: Wed Sep 27 2006 - 15:57:29 EST

"Om Narasimhan" <om.turyx@xxxxxxxxx> writes:

> Hi,
> I am working with a new bios for a server our company build. I am
> confused about the routing of the timer and arch/x86_64/kernel/time.c
> irq setup.
> HPET specification states that if Legacy routing replacement enable
> bit is set, IRQ0 should not be connected to PIN0 of IOAPIC, and IRQ0
> should not generate any interrupts. But in the kernel code, timer is
> hard coded to irq0 (arch/x86_64/kernel/time.c : time_init(), calls
> setup_irq(0,&irq0). 0 being the irq number)
> My question is, should it not be IRQ2 if HPET is enabled and Legacy
> Routing Replacement bit is enbaled?

Legacy Routing Replacement is currently not supported.

Feel free to contribute a patch supporting it though.

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